Re: [RFC][PATCH] memcg remove css_get/put per pages v2

[Balbir Singh]

* KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2010-06-09 15:59:40]:

> +		if (consume_stock(mem)) {
> +			/*
> +			 * It seems dagerous to access memcg without css_get().
> +			 * But considering how consume_stok works, it's not
> +			 * necessary. If consume_stock success, some charges
> +			 * from this memcg are cached on this cpu. So, we
> +			 * don't need to call css_get()/css_tryget() before
> +			 * calling consume_stock().
> +			 */
> +			rcu_read_unlock();
> +			goto done;
> +		}
> +		if (!css_tryget(&mem->css)) {

If tryget fails, can one assume that this due to a race and the mem is
about to be freed?


-- 
	Three Cheers,
	Balbir
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